Telephone system



(No lxtlodel.)v Y 3 Sheets--Sheet'L4 J. F. CASEY.

TELEPHONE SYSTEM. No. 394,832. Patented Deo. 18, 1888.

(No Model.) 3 Sheets-Sheet 2.

J.'P. CASEY.

TELEPHONE SYSTEM.

4Patented Dec. 18, 1888.

NLSQMSL N. PETERS, PholLrLiihngrlphBr. Wnshingun. D. C.

(No Model.) 3 Sheets-Sheet 3.

' J .`F. CASEY.

TELEPHONE SYSTEM. No. 894,882. Patented Dec. 18, 1888.

N. PETERS, FhoILRhognpher, Washington. D, C.

UNITED STATES PATENT OEETCE.

JOI-IN F. CASEY, OF ST. LOUIS, MISSOURI.

TELEPHONE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 394,832, dated December 18, 1888.

, Applicatioh filed April 9, 1888. Serial No. 270,035. (No model.)

1'0 a/Z whom it may concern.-

Be it known that I, JOHN F. CASEY, a citi- Zen of the United States, residing at St. Louis, in the State of Missouri, have invented certain new and useful. Improvements in Telephone Systems, of which the following is suoli a full, clear, and exact description as will enable any one skilled in t-he art to which it appertains to make and use the same, reference being' had to the accompanying drawings, forming Vpart of this specification.

My invention relates more particularly to improvements in trunking between central offices, being more particularly adapted but not necessarily confined to the telephone system known as the Law system and described in United States Patents Nos. 220,874, 278,613, and 319,856, the first mentioned granted to F. Shaw and the last two to F. Shaw and XV. A. Childs.

My invention relates more especially' to an improvement in the method of trunking between central offices described in Patent No. 278,613, aforesaid.

rlhe object of the .invention is to facilitate trunking between central offices, so as to save time and render the service better.

The invention consists, briefi y, in an extended call-circuit between central offices, which extended call-circuit is provided with one or more operators outfits, and also in providing the switch-boards at said central offices with a trunking-section or devices and means whereby trunking-connections can be quickly made at each office.

I will now proceed to describe my invention in detail byreferring to the accompanying drawings, in which- Figure I is a diagrammatic view of' my invention applied to two central offices in which any system of' telephone-exchange may be employed. Fig. II is a diagrammatic view showing my invention applied to the Law system between two large central offices. Fig. III is a diagrammatic view of my invention applied to the Law system between a large central office and a small one, showing also a modification of the switch-board at the large station.

The same figures of reference indicate the same or corresponding parts throughout the several views.

I have designated in the diagram the two offices by central office A and central office B, where the central offices are large ones-such as would be located in large cities; and where a small central office is illustrated I have designated it by a corresponding small letter, as in Fig. III, where I have indicated the same by central office b, which is such an office as would be in a small town where but little telephonie communication is carried on.

Having more particular reference to Fig. I, central offices A and B are to be considered as having any number of subscribers connected with said offices, only a few subscribers being shown to prevent confusion. Any system of connecting the subscribers of the same central office with each other may be supposed to .be employed. When itis desired to connect one subscriber with a subscriber in another central office by the methods now in vogue, great delay and embarassment ensue. the central office. The central office makes connection with the other central office, calls said second office, and asks for the subscriber called, so that the operator at the first central office has to signal the second central office, ask for the desired subscriber, and the second central office then makes the connection, giving the called subscriber one of the trunkwires, the operator at the first-mentioned central office doing the same.v Here we have several operations to reach the desired subscriber, which takes a great deal of time and is very unsatisfactory. In my invention I provide each central office with a call-circuit and eX- tend said call-circuit to the other central office, and there provide said circuit with an operators outfit, the said call-circuit being always intact and extending lpermanent-ly from one central office to the other. By this means, when the central office A, for instance,receives a call for a subscriber in central office B, the central office A calls for the subscriber asked for, and the said call is heard in the central office B at the same time that it is heard in the central office A, so that connection can be made at the same time at cental office B that it is made at central office A, for both operators that make the connections in each office hear the call at the same time. This obviates In the first place, the subscriber calls to Ioo sarei-ie the necessity of the central office A first making connection with central oiiice l5, then calling up said central otiice B, and then waiting until said centralv oiiice li makes the connection. By my invention a connection can be made between subscribers connected with dit'- terent central ollices as expeditiously as between subscribers belon ging' to the same eentral ofiice. As a matter ot' tact, in p 'actice, by my invention, which I have now in constant daily use, I am enabled to make connections quicker' between subscribers belonging to diil'erent stat-ions than those belonging to the same station,

l 2 i in the diagram ot' Fig. I represent trunk-lines, which extend from one central -oliice to another.

7 is the extended call-circuit, which extends permanently between the central ol'lices and .is always intact. It preferably passes around each central office, and maybe provided wit-h one or more operators outfits at each office. It may be suitably grounded at each oiiice or be a complete metallic circuit in itself. I have shown in Fig. I a subscriber belonging to central oiiicc A talking to a subscriber belongin to central office B, and also a subscriber of central othce I3 talking to a subscriber in central ofhce A. It is to be understood in trunking from one otiice to another that certain trunk-wires are to be used-say the wires having` the odd numbers when talking from otiice A to office B and the wires having the even numbers when talking from oiice B to ot'tice A. This being settled upon beforehand no confusion arises. To prevent the operator from breaking in on a circuit or wire when the same is in use, the Law system` employs means to indicate that the line 4isbusy before disturbing the line or breaking in on it, the same being described in Patent No. 319,856 aforesaid. This makes no part of myin vention, but is used `in connection with it to prevent the operator from breaking in on a trunkwire or subscriber when they are busy, so that confusion does not arise, each wire being subjected to a busy test before connection is made. I have shown in Fig. I some oi' the lines provided with one subscriber and some with several. It may be here remarked that 'individual-subscriber circuits may be used, or circuits having several subscribers on the same may be employed. These features make no difference so tar as my invei'ltitm is conccrned.

Having now more particular reference to Fig. II, l 2 3 i 5 U are the truuk-wires, as before, and '7 the extended call-circuit, as previously described. The switch-boards at the two central oiiices are those known as the Law switch-boards, which are described in ci' the switch-board, which preferably hori-,

zontally arranged, one ot said operators bcing on each side ofi' the same. For the sake of clear-ness, however, I will describe each section of the switch-board as presided over by one operator.

Each operator takes care of a certain number of subscribers which are all located in a common call-circuit, there being as many callcircuits as there are sections to the switchboard. An individual talkingcircuit-runs from each sulfiscribcr to the central office. In the diagram I have represented several callcircuits passing around to a multiplicity ot' subscribers therein, but show only two subscribers to each call-circuit connected by an individual talk in g-wi re with the central o llice, said individual talking-wire being shown as grounded at the subseribefs end. The iixed terminal of each talking-circuit is present in every section ot the switch-board, so that the fixed terminal ot' the individual wires occur as many times in the entire switch-boawl as there are sections in the switch-board. The iixed terminals are represented diagrammatically by black dots. At the center of each section of the switch-lnmrd is a series ol' flexible or extensible coimections, which I have represented diagrammatically by small circles to distinguish them trom the fixed terminals. Each subscriber has a flexible or extensible terminal. The fiexible connections of the subscriber in the call-circuit otl a certain operator will occur in the section of the vswitch-board presided over by said operator. I have representedin the diagram by a dotted line the flexible or extensible terminals connected with their respective individual talking-circuits. I have represented the operators taking care of the diit'erent sections by corresponding small letters a', y, and The subscribers in the signaling-eilen it taken care of by operator would have a fixed terminal in each section of the board and a fiexible or extensilille terminal in the section X of the board only. Two subscriliiers are shown in the diagram as havin snch terminals in each section ot' the board.

It will be seen that the sum of the flexible or extensible terminals in the sections X, Y, and Z is equal to the number ot fixed terminals in each section. These features are no part oli my invention, but constitute the Law system, and are here alluded to to ill ustrate how my invention can be applied to such system, and to illustrate the advantages that will accrue by using my invention in conneetimr with the same.

T is the trunking-section. Each ind ividual tral office l2, and there passes around to each IOO I'IO

, board at central office B.

operator at the diff'ierent sections of the switch- This circuit may be a complete metallic circuit or may be suitably grounded, as shown in the diagram. At the central office B the circuit 7 is provided with an operator, fl, located at the trunkingsection T. Each of the operators at the dif'- ferent sections of' the switch-board at the two offices is provided with a transmitter, which may be thrown in the circuit 7 at the will of the operator by actuating a switch near each of said operators. Should one of the subscribers of operator af at central office A call for a subscriber in centraloffice ll, the operator c immediately switches her transmitter in the call-circuit 7 and ainiounces t-he fact, which is heard bythe trunk-operator 8 at central office A, and is simultaneously heard by the trunk-operator 9 in the extended call-circuit atcentral office Il. The operator S thereupon takes a flexible connection of one of the odd trunk-wires and puts it in thc fixed terminal of' the calling subscriber, and the operator i) simultaneously takes hold of the `flexible end of" the correspoi'iding trunk-wire and places it in the fixed tperiniintl of the called subscriber. I have shown clearly in the diagram these connections, having represented by arrows the path of the circuit. Should a subscriber in the call-circuit of operator .c at central office B callfora subscriber in central office A, the same operation is repeated. The operator z puts her transmitter in the call-circuit 7 and announces to the trunk-operator 8, as well as to the trunk-operator 9, that a trunk-connection is to be made, and the trunk-operato r S, simultaneously with the trlink-operator 9, makes the required connection. I have represented also in the diagram a subscriber of operator 2 vin central office B talking with a subscriber belonging to operator 5 at central office A, the path of the circuit being represented by arrows, as in the previous case. It will be noted that any other connections may be made at will.

It will be noted, further, that the trunk-operators have before them all the subscribers in the two offices, and can make any connection rapidly and expelflitiously.

It will be apparent also by my invention that the two can practicallymake the connec-tions in the same time, and thus that no more time is employed in making the two connections than would be in making' one connection, for the two operators move together in their operations and receive the announcement atthe same instant. When any operator receives a call fora subscriber of' her own city, she, of course, does not call into the circuit 7. She leaves her transmitter for said circuit in its normal condition and takes the flexible terminal of' her own Ysubscriber and connects it with the fixed terminal of any of the subscribersin hercity, all of which fixed terminals are before her. She presides only over the flexible terminals of the subscribers in her call-circuit. This lat-ter is the scribers of central office A.

CND.

Law system, and is here referred to to distinguish it from the trunking operation just described.

In Fig. III is shown a modification of the switch-board at central office A, and also a small central office connected by trui'ik-wires with the large central office A. It may be here remarked that the same form of' switchboard as shown in Fig. II could be used at central office A, and, vice versa, the switchboard shown in Fig. III could be used Vin place of the switch-board shown in Fig. II. The modification in the switch-board relates only to the trunking-section circuits and terminals, the switch-board in every other respect being the same as heretofore alluded to. In this switch-board I carry the odd-numbered trunk-wines through every section ot the board, and have a terminal of cach of said odd trunk-wires in each section ofthe board. These terminals are designated by f fb'. These are the trunk-wires that are used in trunking from the large station to the small one. The other wires, 2 it, terminate in a flexible connection at the trunking-section T, as before. The terminals t t3 are fixed terminals. The terminals of the lines 2 l are arranged, preferably, at one side of the section T. The flexible terminals at the center of the section T may be flexible terminals of sub- The operator t to section T will therefore have his subscribers to attend to, and may also make the trunking connections in addition to p his trunking duties. At central office b, I have shown but one section, X, of the switch-board; but any number of sections may be used to accommodate the subscribers of said central office. The trunking-wires l 2 B l terminate in fixed connections, preferably to one side of the switch-board, at central office b. At this central office I have shown but nine terminals and illustrated theconnections for but four subscribers. The number of flexible connections at the center of the board is equal to nine-the number of subscribers at said office, as before explained. The call-circuit 7 passes around the central office A to all the operators, as previously described, and is extended to the central office fi, where it is grounded or provided with a return-circuit and furnished with a receiver, 9, as before. The receiver 8 in said extended call-circuit, referred to in the previously-described arrangement at central office A, is dispensed with. The subscribers call-circuit, presided over by operator .1r at central office l), is extended to centralofiice A, and is there provided with a receiver, l0, so that the receiver ll0 receives everycall that is made bythe subscribers at central office l). The operator to said receiver l0, however, takes no notice of any of those calls except when they are for subscribers at central office A. The operator finay take care of the calls received on the telephone l0 and make trunking-connections in addition to her regular duties, or a sepa- IOO IIO

rate operator may be hicated at receiver i0. \\'here the central of'icc t) is very small, the operzttor .r at said ottice makes connections between all otl her own subscribers, and also makes the trunkingconnectiiinls, the calls of which are received at' telephone il. 'lhc ad- 'vantage ot' the switch-board at central olhce A in this motlilication `is that each operator at the ditterent sections 'can make her own trunking-connections with central ottice b. 'hile n'laking these connections she switches her transmitter in the call-cirtieuit T and notities the operator atI central ottice b that one ot` the subscribers at central ottice 'o is desired. 'lhe operator at said latter station connects the fiexible terminal of said suljiscriber to the trunk-wire, and the connection is made at central ot'fice l) practitirally simultanetms with the connection at central ottice A. 'In the diagram in liigzlll l have shown one subscriber ot operator .r at central office A talking with a subscriber at central ot'l'ice and have shown in said diagram the connections for the same and the path of' the circuit. l have also represented in said diagram a subscriber at central office I talking with a subscriber at central ottice A, and represented the connections and path ot' the circuit as before. ln makingl the latter connection it will be Anoted that the operator at central ot'tice A hears the calls in receiver it) at the same time that the operator .r at central oitice l) does, who presides over the subscribers at said central office. '.lherefore the operator at central ottice A can make the trunking-connection as quickly as the operattnat central office b, and does so simultaneously with the operator at central oiiice ZJ, so that a connection between the subscribers ot' different central ot'iices can be made in the same time as between subscribers ot' the same central ot'tice. observed that the operators a', y, and .5 at. central office A cannot make the trunlti-coiniections except when a subscriber ot the large ottice desires a subscriber ot' the small otiice. When a subscriber of' the small office desires a subscriber ot' the large office, the trunkingconnections at the large of'lice must be made by an operator at the section T. 1t will be obvious that my invention can be used from any central office to any other central oitice, land that by an extension or multiplication ot' the circuits and connections any central ot- Iice may be provided with trunkingtacilit' .s extending to several central offices; also, that two or more extended call-cireuits could be used where one was not sufficient to accommodate the business between cent1-afl ot'Iices.

Having now tully set l'orth my invention and described its operation and advantages, what I wish to claim and secure by Letters Patent of' the United States as my invention is l. The combination, with central-office exchange systems, ot' trunk-wires extending between the same, connections ateach otlice for establishing,I communication between any sub- Itis to be scriber and any ol' said trunk-wires, so that any subscriber may be coupled with any other subscriber at the different ottices, a switchboard-operatiors call-circuit extending between said ccntral offices, passing to switchboard operators, and an operations outiit for said extended call-circuit at each of said oi'- tices, t'or the purpose described.

2. 'lhe combination, withtwo central ottices, ot' trunk-wires extending between said oiiices, connections at said ot'tices whereby any subscriber may be connected with any trunkwire and with any subscriber of the other oftice, a switchboard operators call-circuit at one ot' said ot'tices extended to the other of tice, and passing to switch-board operators at the different ottices, and an operators outfit in said call-circuit at each office, t'or the purpose described.

i5. The comliiination, with central-otiice exchange systems, of' trunk-wires extendingbetween said ot'tices, connections at said offices for connectin any subscriber with any trunkwire, so that any subscrilgier may be connected with any other subscriber at the ditterent ot' tices, a switch board operator-s cafllcircuit passing to switch board operators permanently intact and extending between said ot'- tices, and an olnefratofs outfit permanently located .in said extended eall-circuit at the different ottices, for the purpose described.

si. The combination, with central-oilice exchange systems having switcliboards made up ot' sections, substantially as X Y Z, dac., and provided with a trunking-section, ot' a series ot' trunk-wires extending between said central offices, connections at said central oiiices for giving said trunk-wires to the suliscribers at the dit'terel'it offices, a call-circuit extend ing between said offices, a trunlcoperatos outfit pernntnently in said call-circuit at each othce, a switch-board operators outfit at each section of the switchboard at each of said oliices normally disconnected from said eX- .tended call-circuit, and switches for throwing said last mentioned outfits into said eX- tended call-circuit at will, for the purpose described.

5. The combination, with telephone-exchange systems having a switch-board known as the Law switchboard, made up ot' sections, as X Y Z, &c., and having also a trunking-section, ot' tr tink-wires extending between said exchange systems, fixed and flexible or extensible connections for connecting any subscriber with any other subscriber oi said system, oivierators, as w yz, dsc.,presiding over said sections olf the switch-board and taking care of' a cert-ain number ot' subscribers located in a common call-circuit, an individual talking-wire extending to each subscriber at each system, a call-circuit extending between said systems and passing to each operator, and an operatofs outfit permanently in said extended call-circuit at the trunkinmseotion of each switch board, for the purpose described.

IOO

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G. The combination, with telephone-exchange systems having a switch-board known as the Law switch-board, and made up of sections, as X Y Z, the., and having also a trunkiiig-section, truiik-wires extending between said exchange systems, fixed and flexible terminals for connecting any subscriber with any other subscriber of said systems, operators, as y, and z, each taking care of the different sections and presiding overa certain number of subscribers in a common callcircuit, an individual talking-circuit for each subscriber, a call-circuit extending between said systems passing to each operator, an operators outfit permanently in said call-circuit at the trunking-section at each office, an operators outfit at each section of' the switchboard normally disconnected from said extended call-circuit, and switches for putting said latter outfits in the extended call-circuit at will, for the purpose described.

7. A telepllone-exchange system having a switch-board-operato1"s call-circuit extended to another exchange system and passing to switch-board operators at the different offices, and a receiver permanently in said circuit at the latter office, for the purpose described.

8. The combination, with a large telephone central office provided with the Law system of exchange, substantially as set forth, and a small exchange system of the same character as described, of trunk-wires extending between the two systems, xed and flexible connections for connecting any subscriber with any other subscriber belonging' to the two syst-ems, a call-wire passing to each operator at the large station and extended to the small station, a receiver in said extended call-circuit at the small station, a subscribei"s callcircuit at the small station provided with a receiver thereat and extended to the large station, and a receiver in said last-mentioned exten ded call-circuit located at said large station, for the purpose described.

9. The combination,with central-exchange systems provided with switch-boards known as the Law switch-boards, substantially as set forth, trunk-wires extending between said exchange systems, fixed and fiexible connections, as set forth, for connecting any subscriber with any other subscriber of said systems, a section at which trunkin g is done, one or more terminals for a portion of said trunkwires in each of the sections of' the switchboards, a call-circuit extending to each operator ot' the systems, and an operators outfit located permanently in said extended callcircuit at one or more of' the offices, for the purpose described.

lO. The combin ati on,with a large and small telephoneexchange system provided with switch-boards, known as the Law switchboards7 substantially as set forth, made up of sections X Y Z, tbc., and having a section at which trunking is done, of trunk-wires extending between sai d systems, fixed and flexible connections in the different sections, whereby any subscriber may be connected with any other subscriber of the two systems, a call-circuit extending between the two systems and provided with a receiver at the small station, an operators outfit at each section in the large station for said extended call-circuit, a subscriber-s circuit extended from the small office to the large one, and provided with receivers at each office, and one or more fixed terminals for a portion of the trunk-wires in each section of the switchboard at the large office, for the purpose de-a scribed'.

ll. A switch-board connected with trunkwires adapted for trunking between central offices, provided with flexible terminalsfor said trunk-wires, and having the fixed terminals of subscribers massed in said switchboard around or adjoining said flexible terminals.

l2. A switch-board known as the Law switch-board, made up of sections, substantially as set forth, and connected with trunkwires adapted for trunking between central ofiices, flexible terminals for a portion of said trunk-wires, fixed terminals for the remainder of said trunk-wires in each section of the switch-board, and fixed terminals for the subscribers massed around and adjoining said exible terminals.

lf3. The combination, in the telephone-exchange system, of trunk-wires extending between the central offices thereof, switchboards at said offices of the La'w type, having' fixed and flexible connections in each section, for the purpose described, ifiexible connections for trunk-wires massed in a section, subscribers fixed terminals adjoining' the latter, a call-circuit passing to each operator at each section of the board at each office, and provided with operators outfits, for the purpose described.

l-t. A telcphone-exchange system having the subscribers call-circuit extended to another central-office-exchange system, and provided with an operators outfit at said eentral offices, for the purpose described.

In testimony whereof I have hereunto set my hand and affixed my seal, this 31st day of March, 1888, in the presenceof' the two subscribing witnesses.

JNO. F. CASEY. [Lf s] Witnesses:

A. C. FowLER, HENRY L. BAILEY;

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